Aqueous resin-wax floor coating dispersions



United States Patent AQUEOUS RESIN-WAX FLOOR COATING DISPERSION S.

Arthur C. Pabst, Douglaston, Rudolph Hol'zinger, North Merrick, andElizabeth J; Gavin, PortWashington, N. Y., assignors to Socony-VacuumOil Company, In.- corporated, a corporation of New. York No Drawing,ApplicationJuneZS, 1951, Serial NBA 254,146

4 Claims. (Cl. 260-285) The present invention relates to coatingmaterials of they water dispersed type for use. on. floors. and otherhori- Zontal surfaces, such. as. stair treads, table and counter topsand the like and, more particularly, to such. dispel: sions in which theparticle size of the; resin; particlesmaintained below a criticalmaximum;

The materials in most common use atthe present time are waterdispersions, of waxes of. the. self-polishing type. These polishes arebased primarily on hard natural. waxes such as carnauba, ouricury'orcandelilla wax. Other waxes or wax-like substances may be, incorporatedin lesser amounts; such as waxes derived from petroleum or syntheticwax-like materials. It has been found, however, that these lattermaterials,.while considerably cheaper than thehard vegetable waxes, willinterfere with proper dispersion of the solids or impart otherundesirable charac: teristics- For instance, many of, themv willrequire. comparativelylarge amounts of emulsifiers in order to attainvthe correct particle size necessary to give gloss to the. dried film.Since the majority of commercial emulsi fiers available for this purposeare liquids or semi-solids, it is evident that the incorporation ofemulsifiers in excessive amounts will tend to soften the-deposited'filmwith attendant lowered performance as to protective value and resistanceto dirt pick-up. The use of hard natural waxes as the main film-formingingredients entails other drawbacks besides their scarcity and high,cost, notably that of slipperiness. In order to overcome these: short--comings, wax manufacturers have long sought to utilize natural orsynthetic resins or resinous substances vide. U. S. Patents Nos.2,127,381; 2,137,636; 2,136,450; 2,232,595; 2,273,780; 2,348,756; and2,404,519. For instance, some resins such as shellac, rosin, Manila gum,etc. have been employed, in the: form of an ammoniacal solution, as anadditive to the finished wax dispersion. While these. and similarmaterials. are advantageousfrom the standpoint of cost of the finishedproduct, they tend to. increase further the slipperiness or tackiness orotherwise interferewith the wearing qualities of the. dried. coating;

especially, if incorporated in amounts larger than, say 20..

or 30 per cent of the total film-forming ingredients. Other; resins,notably those of the chemically modified orsynr thetic types, have beenincorporated during the processing of the Wax dispersion, by meltingthem together with the waxes or wax blends employed. Their use,particularly in.

amounts constituting a part greater than 20. or 30per cent, based ontotal solids present, has raised similar ob ections. It was found, forinstance, that the use of materials.

like rosin-modified phenolicsor alkydsin such proportions:

tended to impart resinous characteristics. to. the film. andmade it moresusceptible to temperature. changes. That is'to say, such a film wouldtend. to behardand slippery vin.

winter, while somewhat soft and distinctly tacky in. summertime, It wasfurther observed that many commer cially available resins compatiblewith molten. waxes.

and possessing a melting or softening point sufii'ciently'l'ow to allowincorporation in this manner, when blended in such a manner with waxesexh1b1ted' a phenomenon. known as mutual plasticizing action thusfurther increasing the.

tendency towards excessive tackiness. Resins of higher melting orsoftening pomt could not, generally be used;

because of limitations imposed by the equipment at the:

disposal of the wax manufacturer. It was alsofoundthat many resins, ifincorporated in significant airlouuts,v n; terfered with properdispersion of the comblned res1nwax; phase in a manner similar tothe;one descrihedaaboye n. Pe roleum. waxes...

similarsurfaces suffer. from still. another Im ion, namely, that ofpermissible or desirable concentration, which. in turn Inn-its the:thickne s and. protective value; or he deposited film... It has been fund that, many commercial wax polishes of the. type described whenmadeuptocontain amounts, of; total. solids; in e sQf 2. 1 e -r willwithin a short time, tend to thicken. or even, to gel o.r.-.s.e.t:up to.a solidma s, thus rendering the. product unfit. for-use. Even; during thinitial stages of this. proce.s5 hanges. in the colloidal; st e f he ipe on app ar t talge. place, uch asagglomeration oitheorigin l wax par.-tieles into. larger: r gates, impairing, or destroying the gloss; of:the: dried. film; Whilea, concentration. of. solids in. excess: of theabove figures is; hus impractical because. of. poorstability it is; alsoundesirable. because of. the. color of the waxfilm produced. Naturalwaxesjsuch a carnauba. and. o ricurr y n ol r from light. y l wo; darkbrown. or. greyishrhrown for: the: more available cradles; Thus,.m0stwaxfilms will have a teudencytodis color: the surface to which: they arapp d. e pecially those; which, are of alight color or pastel shade;This tendency is the. more. pronounced the hea ier, thecoating produced,and. it will be thus seen, that, awax polish of higher concentrationwill produce an undesirable efiect, Anotherrecent approach tothe problemof utilizing resins for the protection of flooring andtsimilar surfaceshas been the attemptto employ conventionalcoatingsof the lacquer type.While products of. this. class will permit the application of mostresins or plastics regardless. of softening; p.oint,.they will, asarule, not permit the incorporation of waxes in: significant amounts...They also. have other important disadvantages, chiefly thosetinherent inthe use. of solvents. as the l qu fying, medium. Suchdrawbacks aresolvating or swelling action on the flooring material. itself orthe-binder, used in its composition, asin the caseof rubbenliuoleum,asphalt tile, or similar materials. Still more seriousobjections are thehazardspresented duringmanu; facture, handling, shipping and.application, suchas flammability of the product. and ingredients, andexplosive ness and toxic effects of the vapors, Because of theselimiations, products of this type havenot met with general avor.

It is one. of, the objects of this. invention to provide. preparationssuited for protection of flooring and other horizontal surfaces withoutthe inherent disadvantages of prior art preparations. It is anotherobject of the present invention to provide materials to replace a majorportion or the total amount of expensive and scarcenaturalwaxes withsynthetic resins or plastics without interfering substantially with theproper dispersion of. the. final. product.

Itis a further. object of this invention to replace expensive.

and scarce waxes. wholly or in part substantially without impartingundesirable characteristics to the dried film, such, asloweredprotective value and, greater dirt, pick-up. Another object of.this invention is, to incorporate resinous materials orv plastics in.the. product without regard. for solubility in aqueousalkali, melting orsofteningpoint, or compatability with waxes. inv the. molten stage. Inaddition. it, isv an objectof' this. invention. tov permit the useofhigher. concentrations of active, ingredients; i. e., waxes andresins,etc. and. thedeposition of a heayier film from the. samenurnber ofapplications (or of films ofequal thickness from. fewer applications).without incurring dif-' ficulties of stability of the, finished.preparation or problems. of discoloration; due to the heavier coating.It isv still. am other abject of this invention to provide coatings fromsuch resins or plastics withoutresorting. to the use of expensive andhazardous solvents. Another object. is tov providecoatings, of superior,performance characterictics,v particularly as to gloss. and. spreadingproperties. Other. objectszof this invention will be recognizediby thoseskilled in the art, from thefollowing description;

It, has, now been discovered. that the aforementioned objects can beaccomplishedby the usev ofwax-immiscible resins or plastics prepared bythe process known as emulsion polymerization. 'A brief outline of theprocessknown as, emulsionpolymerization is. given. in The Technology of.Plastics. and.Resins,? Mason Manning, Van Nostrand (.1947pages 34. and.35.. In. this. process,,the. monomer or monomers. which. as.=a rule.are; liquids or substances Prior art wax; coatings for flooring,

of comparatively low melting point generally below the boiling point ofwater, are finely dispersed in water by means of dispersing oremulsifying agents, and polymerized in situ. It has further beendiscovered that dispersions of such wax-immiscible materials, ifsuitably prepared, are compatible with conventional wax polishes of thewater-dispersion type. It has also been found, that resinouspreparations of the type described (aqueous dispersions) can be usedwithout the admixture of wax dispersions. While resin dispersion as suchfor use as protective coatings are not new, their use in the past hasbeen confined to industrial applications. Applications of this sortusually require thicknesses of coatings considerably in excess of thosecontemplated in the present invention, are carried out by such means asroller or knife coating, brushing, spraying, etc. and requireviscosities substantially in the range of conventional coating materialsused in this manner such as lacquers, varnishes, enamels in order toavoid excessive run-off. For this reason, resin dispersions in the pasthave been used in conjunction with bodying agents or thickeners, whilein the present application, the inherent low viscosity is notobjectionable but advantageous since it permits a type of applicationfamiliar to the user of emulsion-type floor waxes, by means of lambswool applicator, string mop, cloth pad and so on. it is also to be notedthat resin dispersions bodied so as to permit application by roller,brush, spray or similar means generally require drying periods ofseveral hours or days at ordinary temperatures. For this reason,force-drying at elevated temperatures is usually resorted to in order toreduce the drying time to a reasonable and economically feasible period.Whereas coatings of the viscosity and general characteristicscontemplated, when applied in the manner intended, will dry to a usablecondition within an hour or less at ordinarily prevailing temperatures.

It has been found that the use of such wax-immiscible resin dispersionsovercomes most of the shortcomings of prior art preparations. Materialsof this type are potentially abundant and cheap, uniform in nature,non-slippery, non-tacky, can be produced to any desirable hardness andtoughness, and possess substantially constant physical characteristicsover a wide temperature range. It can also be seen that suchwax-immiscible materials can be provided in substantially water-whitecolor, and present no processing problems pertaining to high softeningpoint, solubility in alkaline solutions or compatibility with waxes inthe molten stage or solvents required. They combination of several ofsuch wax-immiscible resins,

either alone or in combination with waxes.

In order to make such combinations useful and permanently stable, it isnecessary that the emulsifying, dispersing, Wetting, stabilizing and/orsimilar agents employed in producing these resins and wax dispersionsand mixtures thereof be compatible. Otherwise, coagulation,precipitation, increase of particle size or other undesirable eifectsmay result.

Typical of various formulations within the scope of the presentinvention and illustrative of the comparable characteristics thereof andthose of prior art floor coating dispersions are the formulations andthe characteristics thereof tabulated hereinafter in Table I.

Table I All Parts In Percent By Weight Polish No 3 4 5 7 8 9 Dispersionof Resin A 30% So1ids-.... DlSpBlSlOD of Resin A 20% Solids....- 80 70 Dspersion of Resin B 17% Solids....- 60 D spers on of Resin C 25%Solids...-- 15 0 Dispersion of Garnauba Wax 13% S0l1d$ 50 85 70 20 30Dispersion of Carnaiiba-Mineral Wax 11% Solids 40 Total Solids Content..percent.. 19 17 18. 6 18.0 14. 6 Resin phase percent of TotalSolids... 66 26 45 86.0 78.0 70.0 Wax phase percent of Total Solids.-.-.34 74 14.0 22. 0 30.0

1 Made up according to the following formula:

t. Oarnauba wax No. 1.- i d Oernauba wax N 0. 3 r 5. 0 Oleic acid 1. 25Triethanolami Borax Water Total 100.00

Resin A is a wax-immiscible polymer of methacrylic acid. In the agueousdispersion employed, the resin particles had an average particlediameter of 0.275 micron.

Resii i B is a wax-immiscible resin of polystyrene. In the aqueousdispersion employed, the resin particles had an average particlediameter of 0.21 micron.

Resin is a wax-immiscible copolymer of vinyl acetate and methacrylicacid. In the aqueous dispersion employed, the resin particles were toosmall to be visible at a magnification of 400X.

Table II 0 ar- Pnsh 3 4 5 7 8 9 K L Resin A Rflsln B iiauba Wax Glosst()visual inspect, 2 Excellent- Excellent- Very Good- Excellent. VeryGood- Good Poor- Fair--. Very Good. Very Good. Fair.

cos 5 0, :)Specular Gloss (1 19.7 14.3.-.---- 14.8... 15.2.-.---. 13.111.5.. 13.9-. 10.8.-- 17.3 15.5...--..- 11.6.

coa On Linoleum (2003125).-- 33.4"... 30.2 28.8......- 32.0 242...--."20.7.. 15.2-- 18.9..- 25.6 26.0...... 19.0. 45, 0 Reflectance 0.0300.650 0.651 0-714 -707--- 0.618- 0.699.. 0.754 0.680. 0.657.SwardHardness,Sec.. 17.1 5.8 12.4.0-.-" 22.4 18.9 20.0-. 5.4--. 32.5...60.2 6.1 6.2.

can also be provided in concentrations well in excess of The value for60, 60 Specular Gloss was detercominercial wax polishes. Resindispersions of the type proposed, while containing one or a mixture ofseveral such wax-immiscible resins as the main constituents, may or maynot contain other ingredients. such as plasticizers, stabilizers, etc.in order to modify or enhance the characteristics of said dispersions orof the films deposited therefrom without departing from the spirit ofthis invention.

While in specific cases we elect to employ resin dispersions as the soleconstituent, they can be incorporated in wax polishes in large or minoramounts in order to serve as wax extenders or modifiers.

Wax-immiscible resins produced by emulsion polymerization and suitablefor use in this invention may be of widely divergent types. They mayinclude materials of an elastomeric character, and they may be polymersor copolymers. It has been demonstrated experimentally that awax-immiscible acrylic poylmer, wax-immiscible copolymers if vinylacetate and acrylic resin, and a waximmiscible resin of the polystyrenetype are suitable. However, other wax-immiscible resins are equallysuitable, and may be used without deviating from the spirit mined bymeans of the Hunter multipurpose reflectometer in accordance withProcedure C of ASTM Tentative Method D-523-44T. This method uses a glossscale ranging from 0 to 1000, with higher figures denoting greaterdegrees of gloss and non-metallic coatings ranging from 0 to about 70.

The value for 45", 0 Reflectance was measured according to ASTMTentative Method D-77 l-44T on specimens perpared as specified in U. S.Bureau of Standards Tenative Draft (Revised) of Proposed CommercialStandards for Water Dispersion Floor Wax T84115, April 15, 1946. Thismethod requires the use of a whiteness scale ranging from 0 to 1.000,with the latter value indicating perfect whiteness. The results obtainedindicate the degree of discoloration imparted by the coating to the filmsupporting surface, lower values denoting a less satisfactory product.Materials giving a reading below .600 are considered unsatisfactory.

The Sward Hardness Rocker is an instrument of the pendulum type widelyused in the paint and varnish industry to determine the drying time andultimate hardness of surface coatings. It is based on the principle thatits swing is slowed by tackiness or softness of the supporting surface.Therefore, lower values, as expressed in seconds of total time ofmovement, represent tackier and/or softer films and higher valuesrepresent less tacky and/or harder films. (Reference: H. A. Gardner,Physical & Chemical Examination of Paints, Varnishes, Lacquers andColors, 9 Edition, 1939, pages 109, 117.)

By comparing the characteristics of the coatings produced by twocommercially available fioor polishes (K and L in Table II) with thecorresponding characteristics of the coatings produced by the novelwax-immiscible resin-wax dispersion polishes of the persent invention itwill be found that the novel resin-wax dispersions provide coatings insome respects of at least as good quality and in some respects of betterquality than the coatings provided by the commercially availablepolishes. Thus, for example, the gloss of the coating obtained from thenovel resin-wax dispersions as determined by visual inspection is inevery instance better than that of coatings obtained from commerciallyavailable wax polishes. The specular gloss of coatings obtained from allbut two of the tested novel resin-wax dispersions is better than that ofthe commercial polishes and the specular gloss of the coatings fromresin-wax dispersions 8 and 9 is at least as good as that of coatingsobtained from commercial polishes although the novel resin-waxdispersions contain only about 4 weight per cent wax compared to 11 and13 weight per cent wax in the commercial polishes.

All of these novel dispersions of wax-immiscible resins and waxescontain large percentages of wax-immiscible resin without the inherentdrawbacks of such large concentrations of wax-immiscible resins, such asinterference with proper dispersion of the final product, tackiness orsoftness, and thereby permit replacement of expensive natural waxes to agreat degree. This is accom plished without the use of expensive orhazardous solvents. The solids content is higher in all instances thanthat of representative commercial preparations. In spite of this highersolids content, discoloration is reduced considerably. The gloss, bothon one and two coat applications, is in excess of that of the commercialpreparations. In all cases, the materials given as examples dried in onehour or less, had viscosities substantially equal to conventional waxdispersions, permitting application by conventional means and exhibitedno settling or other inherent instability.

It has been pointed out hereinbefore that blends of wax-immiscible resinand wax dispersions are dependent for stability upon compatibility ofemulsifying, dispersing, stabilizing and/or similar agents. It nowappears that another factor is in evidence, namely, the particle size ofthe water-dispersed resin. It is a well known fact that wax emulsions ofthe self-polishing type, which is the type used in the presentinvention, have a particle size in the colloidal range. The range ofcolloidal particle size is generally given as from 1.0 to 0.001 micron,the upper limit of which by definition, coincides with the limit ofresolving power of the light microscope. It now appears that thewax-immiscible resin particles must be of similar size if usefulcombinations of the two are to be obtained. On the basis of informationnow available, it appears that the resin dispersions found to giveuseful mixtures with waxes, have an average particle size of 1 micron orless, and probably in the range of somewhat below 0.3 micron to 0.03 to0.01 micron. Several resins that have gitien unsatisfactory results havean average particle size above these figures. It appears, therefore,that suitability for the purpose intended does not depend primarily onthe type of wax-immiscible resin but rather on its colloidal state,provided, of course, that requirements concerning the auxiliaryingredients of the dispersion in question are met.

It is to be noted that the resins of the novel resin-wax polishesdiscussed hereinbefore are of the wax-immiscible class. The members ofthis class are typified by those for which data are presented in TablesI and II and are resins which are insoluble or immiscible with waxessuch as carnauba wax, mineral wax, ouricury and candelilla wax attemperatures up to and slightly above the melting point of the wax.

The present application is a continuation-in-part of our copendingapplication Serial No. 16,144, filed March 20, 1948, now abandoned.

We claim:

1. A low-viscosity aqueous dispersion consisting essentially of a hardnatural wax selected from the class consisting of carnauba wax, ouricurywax and candelilla wax, and a wax-immiscible resin produced by emulsionpolymerization selected from the class consisting of polymethacrylicacid, polystyrene and copolymer of vinyl acetate and methacrylic acid,substantially all the wax particles and substantially all thewax-immiscible resin particles present in the aqueous dispersion beingof the same average diameter-and less than 1 micron.

2. A low viscosity aqueous dispersion, as described and set forth inclaim 1, in which the average diameter of both Wax and wax-immiscibleresin particles is about 0.01 to about 0.3 micron.

3. A low viscosity aqueous dispersion consisting essentially of carnaubawax and a wax-immiscible copolymer of vinyl acetate and methacrylic acidproduced by emulsion polymerization, the particles of both the wax andthe wax-immiscible copolymer being of about the same average diameterand invisible at a magnification of 400x, said dispersion comprisingabout 50 to about volume percent of an aqueous dispersion of said waxparticles and about 50 to about 15 volume per cent of an aqueousdispersion of said wax-immiscible copolymer particles, said waxdispersion comprising about 5.0 weight per cent carnauba wax No. 1,about 5.0 weight per cent carnauba wax No. 3 refined, about 1.25 weightper cent oleic acid, about 1.65 weight per cent triethanolamine, about0.75 weight per cent borax, and the balance to make weight per centwater.

4. A low viscosity aqueous dispersion consisting essentially of carnaubawax, mineral wax and wax-immiscible polystyrene resin produced byemulsion polymerization, the average diameter of the particles of thewax and the wax-immiscible resin being about 0.21 micron, and saiddispersion comprising about 40 volume per cent of an aqueous dispersionof carnauba and mineral waxes containing about 11 weight per cent solidsand 60 volume per cent of an aqueous dispersion of wax-immisciblepolystyrene containing about 17 weight per cent of solids.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,540,996 Ryden Feb. 6, 1951 2,606,165 Chapin et al. Aug. 5,1952

1. A LOW-VISCOSITY AQUEOUS DISPERSION CONSISTING ESSENTIALLY OF A HARDNATURAL WAX SELECTED FROM THE CLASS CONSISTING OF CARNAUBA WAX, OURICURYWAX AND CANDELILLA WAX, AND A WAX-IMMISCIBLE RESIN PRODUCED BY EMULSIONPOLYMERIZATION SELECTED FROM THE CLASS CONSISTING OF POLYMETHACRYLICACID, POLYSTYRENE AND COPOLYMER OF VINYL ACETATE AND METHACRYLIC ACID,SUBSTANTIALLY ALL THE WAX PARTICLES AND SUBSTANTIALLY ALL THEWAX-IMMISCIBLE RESIN PARTICLES PRESENT IN THE AQUEOUS DISPERSION BEINGOF THE SAME AVERAGE DIAMETER AND LESS THAN 1 MICRON.